Long-range-ordered alloys modified by Group IV-B metals (open access)

Long-range-ordered alloys modified by Group IV-B metals

Ductile long range ordered alloys having high critical ordering temperatures exist in the (V,M)(Fe,Ni,Co)/sub 3/ system having the composition comprising by weight 20.6 to 22.6% V, 14 to 50% Fe, 0 to 64% Co, and 0 to 40% Ni, and 0.4 to 1.4% M, where M is a metal selected from the group consisting of Ti, Zr, Hf, and their mixtures. These modified alloys have an electron density no greater than 8.00 and exhibit marked increases at elevated temperature in ductility and other mechanical properties over previously known ordered alloys.
Date: May 22, 1981
Creator: Liu, Chain T.; Inouye, Henry & Schaffhauser, Anthony C.
Object Type: Patent
System: The UNT Digital Library
Nonlinear ion-cyclotron waves in mirror machines. Paper IAEA-CN-38/S-1 (open access)

Nonlinear ion-cyclotron waves in mirror machines. Paper IAEA-CN-38/S-1

Experimental results on ion-cyclotron waves observed in the 2XIIB mirror machine are reviewed, and relevant theoretical work is discussed. The work reported generally substantiates the quasilinear diffusion model of mirror-plasma confinement, but also suggests alternatives. The end-loss current required by theory of the drift-cyclotron loss-cone (DCLC) instability agrees with measurements of this current. The experiment indicates that an increased ratio of plasma radius to ion gyroradius improves plasma confinement. However, measurements sometimes show a second ion-cyclotron mode, which is not the DCLC mode. Theoretical work on loss-cone instabilities has concentrated on linear, quasilinear, and fully nonlinear models of increased sophistication and experimental applicability.
Date: May 22, 1980
Creator: Cohen, B. I.; Smith, G. R. & Berk, H. L.
Object Type: Article
System: The UNT Digital Library
Plasma confinement experiments in the TMX tandem mirror. Paper IAEA-CN-38/F-1 (open access)

Plasma confinement experiments in the TMX tandem mirror. Paper IAEA-CN-38/F-1

Results from the new Tandem Mirror Experiment (TMX) are described. Tandem-mirror density and potential profiles are produced using end-plug neutral-beam injection and central-cell gas-fueling. TMX parameters are near those predicted theoretically. The end-plug electron temperature is higher than in the comparably sized single-mirror 2XIIB. Axial confinement of the finite-beta central-cell plasma is improved by the end plugs by as much as a factor of 9. In TMX, end-plug microinstability limits central-cell confinement in agreement with theory.
Date: May 22, 1980
Creator: Simonen, T. C.; Anderson, C. A. & Casper, T. A.
Object Type: Article
System: The UNT Digital Library
Harmonic generation of ion waves due to Brillouin backscattering (open access)

Harmonic generation of ion waves due to Brillouin backscattering

We report results of simulations of stimulated Brillouin backscatter in which we see the second spatial harmonic of the ion density fluctuation and compare with linear, fluid theory. We also describe examples of the competition between Raman and Brillouin backscatter. 21 refs., 3 figs.
Date: May 22, 1985
Creator: Estabrook, K.; Kruer, W. L. & Haines, M. G.
Object Type: Article
System: The UNT Digital Library
Review of geochemical measurement techniques for a nuclear waste repository in bedded salt (open access)

Review of geochemical measurement techniques for a nuclear waste repository in bedded salt

A broad, general review is presented of geochemical measurement techniques that can provide data necessary for site selection and repository effectiveness assessment for a radioactive waste repository in bedded salt. The available measurement techniques are organized according to the parameter measured. The list of geochemical parameters include all those measurable geochemical properties of a sample whole values determine the geochemical characteristics or behavior of the system. For each technique, remarks are made pertaining to the operating principles of the measurement instrument and the purpose for which the technique is used. Attention is drawn to areas where further research and development are needed.
Date: May 22, 1980
Creator: Knauss, K.G. & Steinborn, T.L.
Object Type: Report
System: The UNT Digital Library
Catalytic-cartridge SO/sub 3/ decomposer (open access)

Catalytic-cartridge SO/sub 3/ decomposer

A catalytic cartridge internally heated is utilized as a SO/sub 3/ decomposer for thermochemical hydrogen production. The cartridge has two embodiments, a cross-flow cartridge and an axial flow cartridge. In the cross-flow cartridge, SO/sub 3/ gas is flowed through a chamber and incident normally to a catalyst coated tube extending through the chamber, the catalyst coated tube being internally heated. In the axial-flow cartridge, SO/sub 3/ gas is flowed through the annular space between concentric inner and outer cylindrical walls, the inner cylindrical wall being coated by a catalyst and being internally heated. The modular cartridge decomposer provides high thermal efficiency, high conversion efficiency, and increased safety.
Date: May 22, 1981
Creator: Galloway, Terry R.
Object Type: Patent
System: The UNT Digital Library
Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2 (open access)

Theory of field-reversed mirrors and field-reversed plasma-gun experiments. Paper IAEA-CN-38/R-2

Experimental and theoretical studies of field reversal in a mirror machine are reported. Plasma-gun experiments demonstrate that reversed-field plasma layers are formed. Low energy plasma flowing behind the initially produced plasma front prevents tearing of the layer from the gun muzzle. MHD simulation shows that tearing can be obtained by impeding the slow plasma flow with a plasma divider. It is demonstrated theoretically that a field-reversed mirror imbedded in a multipole field can be sustained in steady state with neutral-beam injection even in the absence of impurities. MHD stability analysis shows that growth rates of elongated reversed-field theta-pinch configurations decrease with axial extension, which indicates the importance of including finite Larmor radius in the analysis. Tilting-mode criteria are dramatically improved by proper shaping, and a problimak shape is proposed. Tearing mode stability of reversed-field theta-pinches is greatly enhanced by flux exclusion. Self-consistent, 1-1/2-dimensional transport codes have been developed, and initial results are presented.
Date: May 22, 1980
Creator: Anderson, D.V.; Auerbach, S.P. & Berk, H.L.
Object Type: Article
System: The UNT Digital Library
Sulfidation of Cadmium at the Nanoscale (open access)

Sulfidation of Cadmium at the Nanoscale

We investigate the evolution of structures that result when spherical Cd nanoparticles of a few hundred nanometers in diameter react with dissolved molecular sulfur species in solution to form hollow CdS. Over a wide range of temperatures and concentrations, we find that rapid Cd diffusion through the growing CdS shell localizes the reaction front at the outermost CdS/S interface, leading to hollow particles when all the Cd is consumed. When we examine partially reacted particles, we find that this system differs significantly from others in which the nanoscale Kirkendall effect has been used to create hollow particles. In previously reported systems, partial reaction creates a hollow particle with a spherically symmetric metal core connected to the outer shell by filaments. In contrast, here we obtain a lower symmetry structure, in which the unreacted metal core and the coalesced vacancies separate into two distinct spherical caps, minimizing the metal/void interface. This pattern of void coalescence is likely to occur in situations where the metal/vacancy self-diffusivities in the core are greater than the diffusivity of the cations through the shell.
Date: May 22, 2008
Creator: Cabot, Andreu; Smith, Rachel; Yin, Yadong; Zheng, Haimei; Reinhard, Bjorn; Liu, Haitao et al.
Object Type: Article
System: The UNT Digital Library
Modification of the GS LT Paired-end Library Protocol for Constructing Longer Insert Size Libraries (open access)

Modification of the GS LT Paired-end Library Protocol for Constructing Longer Insert Size Libraries

Paired-end library sequencing has been proven useful in scaffold construction during de novo assembly of genomic sequences. The ability of generating mate pairs with 8 Kb or greater insert sizes is especially important for genomes containing long repeats. While the current 454 GS LT Paired-end library preparation protocol can successfully construct libraries with 3 Kb insert size, it fails to generate longer insert sizes because the protocol is optimized to purify shorter fragments. We have made several changes in the protocol in order to increase the fragment length. These changes include the use of Promega column to increase the yield of large size DNA fragments, two gel purification steps to remove contaminated short fragments, and a large reaction volume in the circularization step to decrease the formation of chimeras. We have also made additional changes in the protocol to increase the overall quality of the libraries. The quality of the libraries are measured by a set of metrics, which include levels of redundant reads, linker positive, linker negative, half linker reads, and driver DNA contamination, and read length distribution, were used to measure the primary quality of these libraries. We have also assessed the quality of the resulted mate pairs …
Date: May 22, 2008
Creator: Peng, Ze; Peng, Ze; Hamilton, Matthew; Ting, Sara; Tu, Hank; Goltsman, Eugene et al.
Object Type: Report
System: The UNT Digital Library
ECLOUD in PS2, PS+, SPS+: AN UPDATE (open access)

ECLOUD in PS2, PS+, SPS+: AN UPDATE

We present an update of our results for the electron-cloud build-up for several upgrades proposed for the LHC injectors. Specifically, we have re-examined our published results for the ecloud heat load [1] from the perspective of numerical convergence of the simulations vis-a-vis the integration time step {Delta}t. We repeated most of the simulations with ever smaller values of {Delta}t until we reached stable results, indicating numerical convergence; this was achieved at 200-500 slices per bunch, depending on the particular case. In all cases examined, the simulated heat load decreases monotonically, until the limit is reached, as {Delta}t decreases in the range explored, hence the stable results are more favorable vis-a-vis the heat load than the previous ones. This is particularly true for a bunch spacing t{sub b} = 25 ns.
Date: May 22, 2007
Creator: Furman, M. A.
Object Type: Article
System: The UNT Digital Library
Development of a Whole-Wafer, Macroscale Inspection Software Method for Semiconductor Wafer Analysis (open access)

Development of a Whole-Wafer, Macroscale Inspection Software Method for Semiconductor Wafer Analysis

This report describes the non CRADA-protected results of the project performed between Nova Measuring Systems, Ltd., and the Oak Ridge National Laboratory to test and prototype defect signature analysis method for potential incorporation into an in-situ wafer inspection microscope. ORNL's role in this activity was to collaborate with Nova on the analysis and software side of the effort, wile Nova's role was to build the physical microscope and provide data to ORNL for test and evaluation. The objective of this project was to adapt and integrate ORNL's SSA and ADC methods and technologies in the Nova imaging environment. ORNL accomplished this objective by modifying the existing SSA technology for use as a wide-area signature analyzer/classifier on the Nova macro inspection tool (whole-wafer analysis). During this effort ORNL also developed a strategy and methodology for integrating and presenting the results of SSA/ADC analysis to the tool operator and/or data management system (DMS) used by the semiconductor manufacturer (i.e., the end-user).
Date: May 22, 2003
Creator: Tobin, K.W.
Object Type: Report
System: The UNT Digital Library
Quantum Dynamical Behaviour in Complex Systems - A Semiclassical Approach (open access)

Quantum Dynamical Behaviour in Complex Systems - A Semiclassical Approach

One of the biggest challenges in Chemical Dynamics is describing the behavior of complex systems accurately. Classical MD simulations have evolved to a point where calculations involving thousands of atoms are routinely carried out. Capturing coherence, tunneling and other such quantum effects for these systems, however, has proven considerably harder. Semiclassical methods such as the Initial Value Representation (SC-IVR) provide a practical way to include quantum effects while still utilizing only classical trajectory information. For smaller systems, this method has been proven to be most effective, encouraging the hope that it can be extended to deal with a large number of degrees of freedom. Several variations upon the original idea of the SCIVR have been developed to help make these larger calculations more tractable; these range from the simplest, classical limit form, the Linearized IVR (LSC-IVR) to the quantum limit form, the Exact Forward-Backward version (EFB-IVR). In this thesis a method to tune between these limits is described which allows us to choose exactly which degrees of freedom we wish to treat in a more quantum mechanical fashion and to what extent. This formulation is called the Tuning IVR (TIVR). We further describe methodology being developed to evaluate the prefactor …
Date: May 22, 2008
Creator: Gliebe, Cheryn E & Ananth, Nandini
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model (open access)

Ab Initio Study of 40Ca with an Importance Truncated No-Core Shell Model

We propose an importance truncation scheme for the no-core shell model, which enables converged calculations for nuclei well beyond the p-shell. It is based on an a priori measure for the importance of individual basis states constructed by means of many-body perturbation theory. Only the physically relevant states of the no-core model space are considered, which leads to a dramatic reduction of the basis dimension. We analyze the validity and efficiency of this truncation scheme using different realistic nucleon-nucleon interactions and compare to conventional no-core shell model calculations for {sup 4}He and {sup 16}O. Then, we present the first converged calculations for the ground state of {sup 40}Ca within no-core model spaces including up to 16{h_bar}{Omega}-excitations using realistic low-momentum interactions. The scheme is universal and can be easily applied to other quantum many-body problems.
Date: May 22, 2007
Creator: Roth, R & Navratil, P
Object Type: Article
System: The UNT Digital Library
Benchmarking of Resrad-Offsite : Transition From Resrad (Onsite) Toresrad-Offsite and Comparison of the Resrad-Offsite Predictions With Peercodes. (open access)

Benchmarking of Resrad-Offsite : Transition From Resrad (Onsite) Toresrad-Offsite and Comparison of the Resrad-Offsite Predictions With Peercodes.

The main purpose of this report is to document the benchmarking results and verification of the RESRAD-OFFSITE code as part of the quality assurance requirements of the RESRAD development program. This documentation will enable the U.S. Department of Energy (DOE) and its contractors, and the U.S. Nuclear Regulatory Commission (NRC) and its licensees and other stakeholders to use the quality-assured version of the code to perform dose analysis in a risk-informed and technically defensible manner to demonstrate compliance with the NRC's License Termination Rule, Title 10, Part 20, Subpart E, of the Code of Federal Regulations (10 CFR Part 20, Subpart E); DOE's 10 CFR Part 834, Order 5400.5, ''Radiation Protection of the Public and the Environment''; and other Federal and State regulatory requirements as appropriate. The other purpose of this report is to document the differences and similarities between the RESRAD (onsite) and RESRAD-OFFSITE codes so that users (dose analysts and risk assessors) can make a smooth transition from use of the RESRAD (onsite) code to use of the RESRAD-OFFSITE code for performing both onsite and offsite dose analyses. The evolution of the RESRAD-OFFSITE code from the RESRAD (onsite) code is described in Chapter 1 to help the dose …
Date: May 22, 2006
Creator: Yu, C.; Gnanapragasam, E.; Cheng, J. J. & Biwer, B.
Object Type: Report
System: The UNT Digital Library
In-Plant Testing of High-Efficiency Hydraulic Separators, Phase II Annual Technical Progress Report: 2005 (open access)

In-Plant Testing of High-Efficiency Hydraulic Separators, Phase II Annual Technical Progress Report: 2005

Hydraulic separators are commonly used for particle size classification and gravity concentration of minerals and coal. Unfortunately, the efficiency of these processes can be quite low due to poor equipment design and variations in feed consistency. To help alleviate these problems, an industry-driven R&D program has been undertaken to develop a new generation of hydraulic separators that are more efficient and less costly to operate and maintain. These units, which are commercially called the CrossFlow separator and HydroFloat separator, have the potential to improve performance (separation efficiency and throughput) and reduce operating costs (power consumption, water and reagent usage). In Phase I of this project, laboratory and pilot-scale test units were evaluated at various industrial sites in both the coal and mineral industries. Based on promising results obtained from Phase I, full-scale prototypes were purchased and installed by a major U.S. phosphate producer and a large eastern U.S. coal company. The test data obtained from these sites demonstrate that significant performance improvements can be realized through the application of these high-efficiency separators.
Date: May 22, 2006
Creator: Luttrell, G. H.; Honaker, R. Q.; Bratton, R. C.; Westerfield, T. C. & Kohmuench, J. N.
Object Type: Report
System: The UNT Digital Library
Safety Evaluation of the Single Shell Tanks (SST) Modified Sluicing Waste Retrieval System (open access)

Safety Evaluation of the Single Shell Tanks (SST) Modified Sluicing Waste Retrieval System

None
Date: May 22, 2006
Creator: Smith, R. D.
Object Type: Report
System: The UNT Digital Library
Generation of Tones Due to Flow past a Deep Cavity: Effect of Streamwise Length (open access)

Generation of Tones Due to Flow past a Deep Cavity: Effect of Streamwise Length

None
Date: May 22, 2006
Creator: Yang, Y; Rockwell, D; Cody, K Lai-Fook & Pollack, M
Object Type: Report
System: The UNT Digital Library
Particle Simulation of Coulomb Collisions: Comparing the Methods of Takizuka & Abe and Nanbu (open access)

Particle Simulation of Coulomb Collisions: Comparing the Methods of Takizuka & Abe and Nanbu

The interactions of charged particles in a plasma are in a plasma is governed by the long-range Coulomb collision. We compare two widely used Monte Carlo models for Coulomb collisions. One was developed by Takizuka and Abe in 1977, the other was developed by Nanbu in 1997. We perform deterministic and stochastic error analysis with respect to particle number and time step. The two models produce similar stochastic errors, but Nanbu's model gives smaller time step errors. Error comparisons between these two methods are presented.
Date: May 22, 2007
Creator: Wang, C.; Lin, T.; Caflisch, R.; Cohen, B. & Dimits, A.
Object Type: Article
System: The UNT Digital Library
Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes (open access)

Illuminating Solar Decathlon Homes: Exploring Next Generation Lighting Technology - Light Emitting Diodes

This report was prepared by PNNL for the US Department of Energy Building Technologies Program, Solid-State Lighting Program. The report will be provided to teams of university students who are building houses for the 2009 Solar Decathlon, a home design competition sponsored in part by DOE, to encourage teams to build totally solar powered homes. One aspect of the competition is lighting. This report provides the teams with information about LED lighting that can help them determine how they incorporate LED lighting into their homes. The report provides an overview of LED technology, a status of where LED technology is today, questions and answers about lighting quality, efficiency, lifetime etc.; numerous examples of LED products; and several weblinks for further research.
Date: May 22, 2008
Creator: Gordon, Kelly L. & Gilbride, Theresa L.
Object Type: Report
System: The UNT Digital Library
Synthesis of Remote Sensing and Field Observations to Model and Understand Disturbance and Climate Effects on the Carbon Balance of Oregon & Northern California (open access)

Synthesis of Remote Sensing and Field Observations to Model and Understand Disturbance and Climate Effects on the Carbon Balance of Oregon & Northern California

The goal is to quantify and explain the carbon (C) budget for Oregon and N. California. The research compares "bottom -up" and "top-down" methods, and develops prototype analytical systems for regional analysis of the carbon balance that are potentially applicable to other continental regions, and that can be used to explore climate, disturbance and land-use effects on the carbon cycle. Objectives are: 1) Improve, test and apply a bottom up approach that synthesizes a spatially nested hierarchy of observations (multispectral remote sensing, inventories, flux and extensive sites), and the Biome-BGC model to quantify the C balance across the region; 2) Improve, test and apply a top down approach for regional and global C flux modeling that uses a model-data fusion scheme (MODIS products, AmeriFlux, atmospheric CO2 concentration network), and a boundary layer model to estimate net ecosystem production (NEP) across the region and partition it among GPP, R(a) and R(h). 3) Provide critical understanding of the controls on regional C balance (how NEP and carbon stocks are influenced by disturbance from fire and management, land use, and interannual climate variation). The key science questions are, "What are the magnitudes and distributions of C sources and sinks on seasonal to decadal …
Date: May 22, 2008
Creator: Law, Beverly; Turner, David; Cohen, Warren & Goeckede, Mathias
Object Type: Report
System: The UNT Digital Library
Global Cooling: Effect of Urban Albedo on Global Temperature (open access)

Global Cooling: Effect of Urban Albedo on Global Temperature

In many urban areas, pavements and roofs constitute over 60% of urban surfaces (roof 20-25%, pavements about 40%). The roof and the pavement albedo can be increased by about 0.25 and 0.10, respectively, resulting in a net albedo increase for urban areas of about 0.1. Many studies have demonstrated building cooling-energy savings in excess of 20% upon raising roof reflectivity from an existing 10-20% to about 60%. We estimate U.S. potential savings in excess of $1 billion (B) per year in net annual energy bills. Increasing albedo of urban surfaces can reduce the summertime urban temperature and improve the urban air quality. Increasing the urban albedo has the added benefit of reflecting more of the incoming global solar radiation and countering the effect of global warming. We estimate that increasing albedo of urban areas by 0.1 results in an increase of 3 x 10{sup -4} in Earth albedo. Using a simple global model, the change in air temperature in lowest 1.8 km of the atmosphere is estimated at 0.01K. Modelers predict a warming of about 3K in the next 60 years (0.05K/year). Change of 0.1 in urban albedo will result in 0.01K global cooling, a delay of {approx}0.2 years in …
Date: May 22, 2007
Creator: Akbari, Hashem; Menon, Surabi & Rosenfeld, Arthur
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF SAMPLES FROM TANK 16H ANNULUS (open access)

CHARACTERIZATION OF SAMPLES FROM TANK 16H ANNULUS

In support of the closure of Tank 16H, the remaining waste material in the tank annulus must be removed. Samples of the waste material from Tank 16H annulus were obtained and sent to Savannah River National Laboratory (SRNL) to determine the chemical and radiochemical composition prior to further waste removal. The three samples obtained from the Tank 16H annulus show some similarity as to the types of mineral phases present in the materials but differ in the relative amounts of each phase present. The samples from outside the dehumidification duct at two locations in the annulus show very different compositions and estimated solubility in water. This indicates the waste material in Tank 16H annulus may have a wide range of compositions at different locations. The table below provides a simplified description of the composition of each sample. The limited characterization techniques conducted and the complex mixture of materials in each sample makes assigning a definitive composition for each sample difficult. Given the variability in composition with just the three small samples characterized, a more detailed description of any single sample may be of limited value.
Date: May 22, 2008
Creator: Hay, M
Object Type: Report
System: The UNT Digital Library
Enantioselective Intramolecular Hydroarylation of Alkenes via Directed C-H Bond Activation (open access)

Enantioselective Intramolecular Hydroarylation of Alkenes via Directed C-H Bond Activation

Highly enantioselective catalytic intramolecular ortho-alkylation of aromatic imines containing alkenyl groups tethered at the meta position relative to the imine directing group has been achieved using [RhCl(coe){sub 2}]{sub 2} and chiral phosphoramidite ligands. Cyclization of substrates containing 1,1- and 1,2-disubstituted as well as trisubstituted alkenes were achieved with enantioselectivities >90% ee for each substrate class. Cyclization of substrates with Z-alkene isomers proceeded much more efficiently than substrates with E-alkene isomers. This further enabled the highly stereoselective intramolecular alkylation of certain substrates containing Z/E-alkene mixtures via a Rh-catalyzed alkene isomerization with preferential cyclization of the Z-isomer.
Date: May 22, 2008
Creator: Harada, Hitoshi; Thalji, Reema; Bergman, Robert & Ellman, Jonathan
Object Type: Article
System: The UNT Digital Library
WSRC-waste and environmental analytical methods (open access)

WSRC-waste and environmental analytical methods

A list of 491 analytical procedures to directly support waste and environmental analytical work is attached. The list is available from the author as a lotus or excel spreadsheet file.
Date: May 22, 1991
Creator: Spencer, W. A.
Object Type: Report
System: The UNT Digital Library